A missing person appeal has gone out for Kate Nickleby, the infuriatingly meek and virtuous heroine of Charles Dickens' novel Nicholas Nickleby, who has not been seen in public for well over a century. A curator who has spent decades trying to track her down hopes his new exhibition on Dickens and art may spark news of her whereabouts.

The portrait, by one of the superstars of Victorian art, William Powell Frith, will be conspicuously missing from the exhibition Dickens and the Artists, which opens at Watts Gallery near Guildford, Surrey, on Tuesday. The painting, which the gallery's curator, Mark Bills, failed to track down for earlier exhibitions, will be represented only by an 1848 engraving on loan from the National Portrait Gallery, and a 19th-century black and white photograph that shows the painting at Dickens' last home, Gad's Hill Place in Kent.

The house opens to the public for the first time this summer but, while in Dickens' day the walls were covered with paintings, with Kate hanging over the sideboard, all modern-day visitors will see is a rather bleak school dining room.

Dickens had such exacting and precise views of what his characters looked like that he fell out with many artists who attempted to illustrate his work – most notoriously with Robert Seymour, who killed himself after he was sacked from illustrating The Pickwick Papers.

Frith, however, famous for panoramic views of Victorian art such as The Derby Day, teeming with characters and incidents worthy of any of the author's works, remained a friend. Bills believes the picture of Kate and another by Frith of Dolly Varden, a character from Barnaby Rudge, were the only paintings of his characters Dickens actually commissioned.

Both were sold in an auction at Gad's Hill after Dickens died on a sofa in the conservatory there in 1870, worn out by overwork at the age of 58. Dolly Varden is now in the V&A collection and coming on loan to the exhibition, but Kate, recorded as sold to one R Attenborough for £210, has never been seen again.

Frith described Dickens as "one of the greatest geniuses that ever lived" in his autobiography, and recalled that he and his mother wept over the letter asking him to "do me the favour to paint me two little companion pictures".

Dickens came to his studio to collect them. Frith recalled "a young man" (Dickens was 30) "with long hair, a white hat, a formidable stick in his left hand, and his right extended to me with frank cordiality, and a friendly clasp that never relaxed till the day of his untimely death".

He sat down to look at the pictures, and Frith trembled, waiting for the verdict from "a man whom I thought superhuman" until Dickens finally said: "They are exactly what I meant, and I am very much obliged to you for painting them for me."

The exhibition will include works by Dickens illustrators, paintings he owned and admired, photographs and archive material. However, the one contemporary artist Dickens had no dealings with was the one in whose honour the gallery housing the exhibition was built – GF Watts, dubbed by his contemporaries "England's Michaelangelo".

Bills thinks this strange, as the artist and author shared many interests, including a passionate concern for social justice and inequality: Watts' 1849 Found Drowned shows the corpse of a young prostitute who has presumably killed herself, a fate that Dickens' Little Em'ly narrowly escapes.

"They must have been aware of one another, they must have been moving in the same circles, yet I can find no record of their ever meeting, still less conversing," Bills said.

Dickens is conspicuously missing from Watts' assembly of portraits of the contemporary writers, artists and politicians he regarded as heroes, despite being more famous than most of them. "I'm afraid Watts dismissed Dickens as a mere popular writer, and had no very high opinion of him," Bills concluded sadly.

Dickens and the Artists, 19 June to 28 October, Watts Gallery, Compton, Surrey